LUSAKA, May 9 (Reuters) - Vedanta Resources’ Zambia unit, Konkola Copper Mines (KCM), is disputing a bill of almost $18 million slapped on it by tax authorities after an audit, an industry source familiar with the matter, told Reuters on Wednesday.

Zambia’s revenue authority concluded audits of mining companies that prompted it to hit Canadian miner First Quantum Minerals with a tax bill of $8 billion.

A KCM company spokesman declined to comment on the matter, and officials from the Treasury and the revenue authority could not confirm the meeting and the size of the tax bill.

Several African governments, including Zambia, Tanzania and Democratic Republic of Congo, are trying to extract more revenue from their resources, unnerving investors as they hike taxes or withhold VAT refunds.

The source said some other mining companies were also disputing the tax bills but was not sure whether they would be part of a planned Wednesday meeting with the finance minister. (Reporting by Chris Mfula Editing by Ed Stoddard and Louise Heavens)